A World to Explore

Archive for June, 2013

MITZPE RAMON, ISRAEL–These are the shining faces of Team Israel 2013 of the Wooster Geology program. From the left is wind-challenged Lizzie Reinthal (’14) from Ohio, Oscar Mmari (’14) from Tanzania, and Steph Bosch (’14) from Pennsylvania (and soon to be an Arizonan). We arrived this afternoon in our destination town of Mitzpe Ramon in the Negev Highlands of southern Israel. This is our first geological stop: a short walk from the hotel to the northern rim of the magnificent Makhtesh Ramon, a deep erosional feature often called the “Grand Canyon of Israel”. If you look back in our Israel blog entries (such as this one) you’ll see this is a traditional setting for our first images! (And the students get their first geological examination on an Israeli outcrop.)

We are in Israel for two weeks pursuing research as part of Wooster’s Senior Independent Study program. Lizzie will be looking at the taphonomy of crinoids in the Jurassic Matmor Formation, Oscar will be studying the origin and economic value of an extensive set of Cretaceous phosphorites, and Steph will be studying rare but important bryozoan fossils from the Matmor Formation, which was deposited near the equator during the Jurassic.

Getting to this spot in the middle of the desert took lots of planning. (Thanks, Suzanne Easterling and Patrice Reeder!) Oscar flew to Tel Aviv from Tanzania via Ethiopia a few hours before us. I was worried about his connections and getting through immigration, but it worked out splendidly — Oscar was there to greet us as we emerged from the arrivals gate. We then packed into a rental car and drove south about three hours to Mitzpe Ramon. The weather is excellent — far cooler than the deserts today in the southwestern USA!

These impressive teeth are from the mosasauridPrognathodon and were found in the Upper Cretaceous phosphorites near Khouribga, Morocco. They are not actually a matching set — I just arranged them to look fearsome.

Prognathodon (the name means “front-jaw tooth”) was a very large mosasaurid, with some specimens up to 12 meters in length. They were cosmopolitan in extent, being found throughout the world in Campanian to Maastrichtian deposits. They lived in deep waters as shown by some specimens with strengthening bony rings around their eye sockets. They were essentially sea-going lizards, and big ones at that.

Note that the teeth are stout and blunt. They were not adapted for tearing flesh but rather crushing hard-shelled prey they found on the seafloor. One skeleton was found with some stomach contents intact, including a sea turtle, a variety of fishes, and an ammonite. This is not the usual diet of other mosasaurid genera which were nektic (swimming) predators.Prognathodon was named in 1889 by the famous Belgian paleontologist Louis Antoine Marie Joseph Dollo (1857-1931). Paleontology and History of Life students will immediately recognize that name because of Dollo’s Law: “evolution is not reversible”. (Or its corollary: extinction is forever!) He started his career as an engineer, graduating at the top of his class in 1877 from the École Centrale de Lille. He worked as a mining engineer and, as luck would have it, quickly discovered an extraordinary mass burial of the dinosaur Iguanodon. Studying this genus and other fossil reptiles became his passion. In 1882 he became an assistant naturalist at the Royal Belgian Institute of Natural Sciences in Brussels. One of his many remarkable contributions was to begin to think of fossils as once living organisms in ecological networks. In this sense he essentially founded paleobiology. In 1912 he received the Murchison Medal from the Geological Society of London. Not too shabby for an engineer.

Two subjects of previous Fossil of the Week posts are combined together here: a belemnite (the elegant Hibolites hastatus) and barnacle borings (the ichnofossil Rogerella). This specimen is from the Jurassic of Moneva Teruel, Spain.

(Living belemnites reconstructed by Bogdanov on Wikipedia)

Belemnites are extinct cephalopods, oddly enough. The specimen is the guard or rostrum — a calcitic internal skeleton that gave the squid-like animal rigidity. Because they are made of solid, stable calcite, these guards can be extremely common in the fossil record, especially in the Jurassic and Cretaceous. Some people call these “belemnite battlefields”, probably because the fossils look so much like bullets.

Hibolites hastatus was named by Henri Marie Ducrotay de Blainville (1777-1850) in 1827. He was a French naturalist with many accomplishments, especially in anatomy and systematics. He spent most of his career in the Faculty of Sciences at Paris, where he was a colleague (and eventual ideological enemy) of the epic Georges Cuvier. In 1830 he took over from the “father of invertebrate zoology” Jean-Baptiste Lamarck as the chair of natural history. Clearly he ran in powerful circles.

The yellow features in this close-up above are holes drilled by acrothoracic barnacles, which were then filled with fine-grained dolomite. The trace fossil thus formed is known as Rogerella. It is found from the Devonian all the way to today. Its presence on these belemnite guards shows that these structures laid for enough time on the seafloor that they could be colonized by barnacles. They are thus an indicator of the taphonomy (or history from death to discovery) of these fossils.

CATANIA, SICILY, ITALY–The IBA meeting has now ended and, as this is posted, I should be winging my way home across the Atlantic. It was a fantastic experience. This is a unique organization, of which I’m now proud to be a member of council. It is a combination of paleontologists and biologists who share a passion for the Phylum Bryozoa in all its manifestations. We had 77 oral presentations and dozens of posters spread among 80 participants, including students, academics, museum scientists, and very keen citizen scientists. The “international” component is taken very seriously: of the 80 people present, 27 countries were represented.All the sessions were held in the Palazzo delle Scienze building shown at the top of the page. We shared it with the regular student body, so it was a lively place. Directly above is the back wall of our meeting room with images of famous scientists who lived in Italy, from the Greeks to the 20th Century.Italians leave no ceiling unpainted. I’m not sure who the people are depicted above us, except that Amerigo Vespucci must be the one holding a map of the Americas. This room certainly makes you feel part of the international scientific enterprise.Here is one of our participants, Kevin Tilbrook, giving a presentation. All our communications were in English. Imagine the challenge of talking in your second or third language with someone else doing the same thing. I am continually amazed by the language skills here.My talk was on Friday morning, June 14. My first slide is shown above. My friend Paul Taylor and I examined two purported bryozoans common in the Paleozoic and showed that they were certainly not members of that phylum, despite some superficial resemblances.This is our conclusion slide. As you can see, it is relatively easy to say what something is not, but quite another to say what it is!The IBA conference dinner is always a big event. This one was among the most spectacular. We had dinner in the historical Palazzo Biscari. This is a view from the terrace towards the central Duomo complex.The ballroom is a Baroque fantasy. To complete the image, dinner was preceded by a choral performance from a Sicilian choir tucked back in the alcove. They sang many, many pieces, including some national favorites from countries represented among us.

And here is the group photo. Like many, I wasn’t ready for this shot, so I’ll be impressed if anyone can find me in here!

Our meeting was a spectacular success in terms of the science shared and learned, and the Sicilian cultural experiences. Thank you very much to organizers Antonietta Rosso and Rossana Sanfilippo from the University of Catania!

CATANIA, SICILY, ITALY–The very last field trip stop — and final event — of the International Bryozoology Association Conference was a trip to the south side of Mount Etna. We drove to a spot that had significant activity in 2000 and 2001. Several lateral craters appeared on the side of the mountain, and the lava flows buried parts of a restaurant and shop complex. They threatened to destroy the base of a cable car system, but firefighters with hoses managed to divert the flow by cooling it with water.My Belgian friend Hans De Blauwe and I decided to choose one of these smaller craters and hike to it within our allotted visit time. We picked this one in the center because of its symmetry and the flows that streamed from it. All of these features in and around this cone formed in 2001.We soon saw that our cone was the first of at least three cones descending in a row down the slope. The lava flow shows very distinct levees on its sides where the lava lapped over its banks and cooled, creating a walled channel.There are many car- and house-sized boulders of non-vesicular basalt scattered about. I assume these were thrown from the throats of explosive craters.We found this very cool lava tube, indicated first by a long walled channel that apparently represents a collapsed portion of the tunnel. A lava tube is formed when the periphery of a flow cools into hard rock and the still-fluid interior empties. We explore a beautiful ancient example on our Mojave Desert field trips.Our lava tube is open at both ends. Here Hans is crouching in the larger of the entrances.I took a flash image of the interior. You can see small “lavasicles” (cooled drips of lava) on the ceiling, along with a white crust of some sulfurous minerals.Here Hans is picking his way through the aa flow. In the lower right is another lava tube that extends back about three meters.The flowers on this volcanic slopes are very interesting. Hardy pioneers, they are. There are numerous clusters of these mounds of greenery. It appears that the plants settled on a bit of ash and then grew centripetally. The surrounding ash was eroded away, but the roots of these plants held onto their patches, eventually producing mounds as the surrounding sediment was removed.The mounds are made mostly of this spiny flowering plant. Maybe Hans will provide me with names later.These purple flowers often form in rings around the bases of the mounds.Nice white flowers on the 2001 ash layers.Somehow there are always daisies around, even in the most surprising places.Finally, here is a view from our craters toward Catania and the coast. A 2001 lava flow is directly below us. In the middle distance you can see a series of small cones, many of which were active in historical times. Catania is certainly in a volcanic hazard zone. The geologists, though, worry far more about earthquakes here than eruptions. An eruption, after all, gives you much more warning than a sudden and devastating ‘quake. Considering all this, and despite the occasional tornado and blizzard, Ohio looks like one of the safest places on Earth.

And to beautiful and much wetter Ohio I now return.

[A late addition to this post (June 23, 2013). Above is a close-up of ash erupted from Mount Etna in April 2013.]

The students hiked the Kayenta trail to the Emerald Pools. Credit: T. Hall

This is the Court of the Patriarchs, so named for figures from the Old Testament by Frederick Vining Fisher in 1916. Abraham Peak is on the far left. Isaac Peak is in the center. Jacob Peak is the white peak that can be viewed just beyond Mount Moroni on the right.

View of The Narrows, a trail that winds through slot canyons in the famously cross-bedded Navajo Sandstone.

The Wooster crew cools off in the Virgin River at the end of an awesome day in Zion. Credit: T. Wilch

CATANIA, SICILY, ITALY–Today we had our last field trip associated with the 2013 International Bryozoology Conference. We traveled to the east coast of Sicily at Castelluccio, which is south of Catania and north of Syracuse. The weather could not have been better. It was, as a commenter has said, “impossibly beautiful”.

The view above is of Early Pleistocene limestones resting on tholeitic basalt flows. As our guides said, in this place we could see the interplay of extensional tectonics, regional uplift, and glacially-controlled sea-level changes. The visuals were stunning. In the background you can see the east flank of Mount Etna.The limestones were of shallow-water origin and very diverse. One layer was almost completed bioturbated (biologically stirred up) by crustaceans, producing a trace fossil of connected tunnels called Thalassinoides.Fossils were abundant in some units. Here is an horizon rich in scallop shells. These shells are often preferentially preserved because they are made of hardy calcite rather than chemically unstable aragonite like most other mollusk skeletons.The interactions between the basalt flows and the calcareous sediments were fascinated. Above you see a black basaltic dike cutting vertically through the limestones. Why there are no visible baked zones is a mystery to me.In this image we have basalt above and sediments below. The pink color of the limestones tells us they were cooked by the hot lava that flowed over them.There are a variety of post-depositional geological processes operating at this outcrop. One of them is the superimposition of beachrock during sea-level highstands. Beachrock is a cemented sediment formed in the surf zone by precipitation of carbonate. This particular beachrock was plastered onto an eroded limestone cliff like stucco. You can see black basalt among the diverse clasts.Over it all rules Mount Etna, here viewed from the top of the outcrop. It was unusually smoky today, which does not show well in our photographs because of the murky haze. We headed to this behemoth for the second and last stop of our field trip.

More fossil fish teeth this week. This impressive, barbed tooth is from the ancient chondrichthyan sawfishOnchopristis numidus (Haug, 1905). It was found in the Tegana Formation (Cenomanian, Upper Cretaceous) near Kem Kem, Morocco (and is yet another contribution from our alumnus George Chambers).These are all rostral teeth, meaning they are the sideways teeth on each side of the snout (rostrum) of the sawfish. They each have a barb for entangling prey. Like modern sawfish, O. numidus would have lived along the bottom and occasionally thrashed about, wounding smaller fish and crustaceans so that it could catch and eat them.

Onchopristis numidus was the largest sawfish known, making it a formidable predator.

Of course, seeing it against a human profile makes it more real!

Despite its size, O. pristis had a famous nemesis: the dinosaur Spinosaurus. Barbed teeth of the sawfish have been found embedded in the jaws of this beast. The above image is from the show Dinosaur Planet, as is this Youtube clip of the two struggling (with one clearly losing).

And yes, Spinosaurus is coming as a future Fossil of the Week!

References:

Martill, D.M. and Ibrahim, N. 2012. Aberrant rostral teeth of the sawfish Onchopristis numidus from the Kem Kem beds (? early Late Cretaceous) of Morocco and a reappraisal of Onchopristis in New Zealand. Journal of African Earth Sciences 64: 71-76.